Young Americans are a generation steeped in sympathy for evil: drug dealers sell drugs because they come from hopeless neighborhoods; pedophiles abuse children because of their own childhood abuse; and killers kill for want of hugs.

There can be wisdom in the understanding of evil available through sympathy. Understanding the disposition of disenfranchised teenagers to drug dealing can – in theory – spur neighborhood redevelopments. Youth centers, guidance counselors, positive adult influences and all that lot are sometimes (and sometimes is better than never) proven to keep young people in school and out of trouble. Likewise, knowledge of the roots of pedophilia can improve treatment and prevent recidivism among offenders.

The lesson is global. Terrorism, like gang violence, is frequently born of hopeless poverty, taken advantage of as motivation by terrorist recruiters. It’s no coincidence virulent terrorism is born of regions whose young people enjoy few luxuries and are harshly restricted by their governments. Providing for the hope and upward mobility of foreign citizenry can alleviate the anger of its youth, and happier young people with bright prospects are less likely to sign on for terror campaigns.

The recent bringing to justice of Osama bin Laden is an opportunity to internalize that lesson, and to reaffirm a second. With regard to the first, developed countries could do worse than remember that trade practices and national policies which foster friendly relations abroad will lead to foreign climes less likely to produce violent extremists.

The second, which bears reaffirming amidst sympathy, is: despite our incidental understanding of it, there exists evil in the world which can – indeed, must – be eradicated fully and finally, no matter its cause, because of its inability to coexist with good. In that light, bin Laden’s epitaph should read like a rabid dog’s: it was a shame he took rabid and it would have been better for all had the conditions which allowed for the existence of the disease been eradicated, but – once rabid – he had to be put down.

Since assuming control of the nation’s armed forces, President Obama has authorized the use of more Predator attack drones than any military chief before him, and for good reason: the drones are efficient and deadly, and they keep American soldiers out of harm’s way.

Each Predator is controlled by two “pilots” who use joysticks and video screens to steer it from a remote base. A trigger attached to the joysticks fires its missiles. The images pilots use to guide the robot planes are gathered by the Predators, beamed to a satellite, and then re-directed through 12 time zones to the control bases in states like California. This takes about a second.

The U.S. Predator drone.

Each Predator carries one 500-pound bomb, or an attachment of equally deadly Hellfire missiles.

Though not without obvious merit, President Obama’s liberal deployment of the machines presents two dangers, and one tertiary benefit.

The first danger remote-controlled war robots present is what game theorists call “signaling.” By refusing to commit our own blood to a conflict, we signal to an enemy that we lack resolve. This is heartening to them; the under-dog martyr mentality often inspires soldiers and spurs armies to fight on. Imagine the Jews in the mountain caves of Masada, so enraged by Rome that they took their own lives rather than be captured; or, the few Spartans who stood against thousands of Persians at Thermopyle, fortified in the throes of patriotic resolve. When soldiers sense they are more dedicated to a cause than their enemies, their fervor can prolong and worsen conflicts, even in the face of overwhelming odds.

The second, and more pressing, danger is that lasting peace isn’t won by soldiers, but by the statesmen who come after. If that’s not done properly, peace deteriorates quickly. This is old news, but consider: for every Al Qaeda operative killed by Predator drones, two more appear. This is because the people they recruit believe in Al Qaeda and hate America. The equation makes it ironically impossible to win a war of attrition with these terrorists: they’re an Arabic Hydra, growing two heads for every one chopped off. By killing them, we make them stronger. The only way to beat something like that is to prevent new heads from growing.

In Afghanistan, the answer is to reverse potential recruits’ mindset. They need to be taught to believe in America and hate Al Qaeda. This is a hard lesson to teach people who see robot planes flying overhead, firing missiles which often either miss their mark completely, and destroy an innocent building next-door, or kill civilians who happen to be in the vicinity of the drone’s target. Predator drones are wonderful for eliminating high-level enemies, but not for winning the hearts and minds of locals, and real victory requires both. This means boots on the ground… but construction boots, not combat boots: friendly faces who, after the fighting has cooled down, help build dams, schools, hospitals, roads, water treatment plants, and governments. Without this shift, any peace bought in any country becomes worthless quickly.

Afghanistan is a place we should be in. We need a friend in an unstable (and often violently anti-Western) region to be our eyes and ears (and military staging area, if necessary). We need to have friends near all that oil, which is a national interest. We need to help it form a stable, just government, which is a humanitarian interest.

We can’t do that with robots. We can only do it with people. Each is a necessary component, and the overwhelming success of one shouldn’t detract from the necessity, at the appropriate time, of the other. Lasting military victory without a sustainable humanitarian interest is impossible, just as sustainable humanitarian interests are impossible without a lasting military victory.

The third danger, and possibly too the drones’ most notable merit, is that they allow American forces to become engaged in conflicts which would have otherwise quickly become unacceptable quicksand death-traps. Some countries historically counted on drawing foreign soldiers inland and then making them pay so heavily for the intrusion that their chiefs cut their losses; think of English redcoats during the American Revolution, United States troops in Vietnam, the British, Russians, and (it’s starting to seem) Americans in Afghanistan, the Nazis in Stalinist Russia, and the Persians at Thermopyle. Each was a superior force attacking a smaller enemy. And each force was drawn so far into that enemy’s home field, and suffered such great losses as a result, they withdrew.

To countries like these, Predator drones announce the end of the tactic: Americans, if drawn into such a fight, will not be forced to cut and run from a mountain of casualties. Rather, they will stay and fight, and fight, and fight for as long as there are missiles available to load onto drones… and none of them will die doing it.